The website of Russia’s highest-profile independent newspaper, Novaya Gazeta, has been paralyzed for a week by a sustained attack, said deputy editor Andrey Lipsky. Monday was the seventh day of a denial-of-service attack from an unknown source.

The paper, which comes out three times a week, relentlessly criticizes the Kremlin, often detailing top-level corruption in embarrassing exposes and investigations. Its reporters have been harassed, attacked and even killed in crimes that police rarely solve.

A denial-of-service attack simulates millions of people visiting the website at the same time, overloading the server and causing it to crash. Novaya Gazeta routinely records 250,000 visits per week. Last Thursday saw 1.5 million visits per second.